Although the political polarization literature has provided important insights in understanding the structure of political attitudes in the United States at the aggregate level, and how this has changed in recent years, few attempts have been made to examine how each individual subjectively perceives political space and how she locates herself vis-à-vis her political in/out groups at the individual level. To examine such subjective polarization, this paper proposes an approach that examines the trifold relationship between a political actor and the two major political parties. Such relational properties are studied by looking at how each individual locates herself in relation to political in/out groups. Using the American National Election Studies Dataset, this paper sheds new light on the patterns and trends of mass polarization in the United States and demonstrates that subjective polarization has a distinct contribution to partisan animus, or "affective polarization."